Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Department of Biomedical Sciences, Rigshospitalet and University of Copenhagen, Blegdamsvej 9, 2100, Copenhagen, Denmark.
J Nucl Cardiol. 2019 Dec;26(6):1934-1942. doi: 10.1007/s12350-018-1359-8. Epub 2018 Jul 2.
Rubidium(Rb)-positron-emission-tomography (PET) is prone to some of the same imaging artifacts as single-photon-emission-computed-tomography myocardial perfusion imaging (MPI) including interference from excessive subdiaphragmatic activity. Our aim was to determine associations between clinical parameters and MPI interference including any potential correlation between interference severity and stomach volume.
Two hundred men and women fasted two hours prior to standard clinical Rb myocardial perfusion rest/stress PET. Images were analyzed for radiotracer interference between left ventricle myocardium and extracardiac activity. Furthermore, volume of the stomach was measured. Interference, predominantly caused by Rb activity in the stomach, was less severe in stress PET compared to rest (absent in 46% vs 31% of patients during stress and rest, P < 0.05). In addition, a large stomach volume was associated with more severe interference in rest (P < 0.05) while a high body mass index was associated with less interference.
Among clinical parameters associated with patient size, BMI was the strongest predictor of MPI interference. Furthermore, a large stomach volume was associated with more severe MPI interference, suggesting that sufficient fasting prior to imminent Rb PET may be important to reduce interference from adjacent radiotracer activity and consequently improve interpretation of MPI results, especially in small patients.
铷（Rb）-正电子发射断层扫描（PET）与单光子发射计算机断层扫描心肌灌注成像（MPI）一样，容易受到一些相同的成像伪影的影响，包括来自过度膈下活动的干扰。我们的目的是确定临床参数与 MPI 干扰之间的关联，包括干扰严重程度与胃容量之间的任何潜在相关性。
200 名男性和女性在进行标准的临床 Rb 心肌灌注静息/应激 PET 前禁食两小时。分析图像以确定左心室心肌和心脏外活动之间示踪剂的放射性干扰。此外，还测量了胃的体积。干扰主要是由胃中的 Rb 活性引起的，在应激 PET 中比静息 PET 时更轻（应激时无干扰的患者比例为 46%，静息时为 31%，P<0.05）。此外，胃体积较大与静息时更严重的干扰相关（P<0.05），而身体质量指数较高与干扰程度较轻相关。
在与患者体型相关的临床参数中，BMI 是 MPI 干扰的最强预测因子。此外，胃体积较大与更严重的 MPI 干扰相关，这表明在进行 Rb PET 前进行充分禁食可能对减少来自相邻放射性示踪剂活性的干扰并因此改善 MPI 结果的解释很重要，特别是在体型较小的患者中。
